Method of making straw-like article of nylon continuous filaments



Aug. 8, 1967 c. M. IRWVIN METHOD OF MAKING STRAW-LIKE ARTICLE OF NYLONCONTINUOUS FILAMENTS Filed April 4, 1962 INVENTOR. (LA UDE M- IRWl/V ,Jm. "I'M- E? ATTORNEy United States Patent 3,335,042 METHOD OF MAKINGSTRAW-LIKE ARTICLE OF NYLON CONTINUOUS FILAMENTS Claude M. Irwin,Pensacola, Fla., assignor, by mesne assignments, to Monsanto Company, acorporation of Delaware Filed Apr. 4, 1962, Ser. No. 185,031 3 Claims.(Cl. 156-161) This invention relates to the production of a straw-likearticle from nylon continuous filaments. More particularly, the presentinvention relates to a straw-like article made from parallel arrangedmulticontinuous filament nylon yarn bonded together by means of atreatment with a bond-inducing agent of a particular class and to amethod of producing such article.

It is known to make artificial straw of viscose rayon by extruding aviscose spinning solution through an L- shaped orifice in a spinneret.Such product consists of a continuous heavy filament folded duringspinning and resembles a silk-like straw. In some cases there have beendisclosed multi-filament versions of this. Also, it is known to meltspin a narrow ribbon-like structure from nylon by using a slot of propersize and shape or by coalescing a plurality of melt spun filamentsbefore they are solidified. In either of these known melt spinningprocedures, a satisfactory narrow, flat strcuture is expensive anddiflicult to produce. Extremely costly melt spinning spinnerets arerequired. Moreover, it is difficult to arrange enough slots in aconventional spinneret blank to render the melt spinning economicallyfeasible.

It is an object of the present invention to provide as an article ofmanufacture a new and useful straw-like article from nylon continuousfilaments.

It is another object of the present invention to provide a new anduseful method of making an article simulating to some extent a straw andmade from parallel arranged multicontinuous nylon filaments.

Other objects of the invention may become apparent from the followingdescription.

In general, these objects are accomplished in the provision of astraw-like article or fillet composed of multicontinuous filament nylonyarn bonded together in a certain wayeThe yarn has a plurality ofsubstantially straight individual continuous filaments disposed in asubstantially parallel relation with respect to each other andpreferably in a substantially parallel relation with respect to the longaxis of the article. The article is elongated, narrow and flat, beinglaterally at least two times as wide as it is thick and is composed ofat least two filaments. The longitudinal dimension of the narrow, flatarticle can be any suitable length. While there is no definite upperlimit for the denier of the article with bands having deniers in excessof a million being contemplated, the denier of the article for practicalreasons should be. at least 15. It is preferred that the yarn from whichthe article is made have little or no twist, although the yarn canexhibit some twist without adverse effect. The individual filaments arefused together by means of a treatment with a multihydroxybenzenecompound. First, a suitable nylon yarn is formed. A fluentmultihydroxybenzene, preferably in solution, is applied to the yarn. Forconvenience, the application of the benzene compound is made while theyarn is traveling longitudinally. Pressure of about 0.5 to 100 poundsper square inch and heat at about 50 to 250 C. are applied to the yarnshortly after the application of the multihydroxybenzene compound tounite the filamentary material at points along the length thereof and toinduce evaporation and removal of the solvent of the multihydroxybenzenecompound. The resultant straw-like structure possesses a coherency amongthe strands that is difiicult to overcome without the per- 3,335,042Patented Aug. 8, 1967 ice formance of considerable work. Any residualbond-inducing agent on the structure is not obnoxious and does notappreciably interfere with the dyeability ofthe fabric. While theresultant straw-like structure can be used without further processing inthe construction of fabric by braiding, plaiting, knitting, or weaving,additional but optional treatments may be employed, such as washing,applying a softening agent, or the like. Fabric made from the straw-likestructure can be used in making hats, bags, shoe uppers, curtains,artificial grass, carpets, upholstery, etc.

The present invention will be further illustrated by reference to thedrawing wherein:

FIGURE 1 is a schematic view of apparatus suitable for use in carryingout the method of the present invention;

FIGURE 2 is a perspective view of a straw-like structure of theinvention; and

FIGURE 3 is a cross section of the structure shown in FIGURE 2.

As illustrated, a package of yarn 10 wrapped about bobbin 12 is providedas a convenient source of a bundle of nylon filaments 14. The bundle offilaments can be unrolled from the bobbin or withdrawn overend.Obviously, the bundle 14 can be advanced directly from a filamentformingmachine involving spinning and drawing operations without anyintermediate package being formed. The-movement of the bundle can becontrolled by 'the use of a yarn forwarding device. As shown, a pair ofdriven nip-forming rolls 16 are operated at a predetermined peripheralspeed to deliver the bundle of filaments at a controlled rate from thesource of supply thereof. The bundle of filaments is then passed overand engages ,a wick material 18 which extends into a container 20holding a supply of fluent multihydroxybenzene 22. The bundle is wetwith the multihydroxybenzene. 1

In order to obtain the desired width and thickness relation for suitablestraw, the bundle of filaments is flattened, if the bundle needs to beso-shaped. One way of flattening the bundle is to run the bundle acrossa snubbing surface such as provided by draw pin 24. As illustrated thebundle is wrapped one time around the pin which is nonrotatably mountedand may or may not be heated. To complete the fusing of the filamentstogether, the bundle next is passed around forwarding rolls 26 and 28 aplurality of times. One of the rolls is positioned at an angle withrespect to the other for proper longitudinal advancement of the bundlealong the rolls. One or both of the rolls can be suitably heated in aconventional manner. An electrical resistance means within the rolls canbe conveniently used for this purpose. If additional lateral pressuringof the bundle is required, convention- .al means can be associated withthe rolls to squeeze the bundle while it is being heated.

Next, the bundle of filaments which at this point in the process hasassumed its straw-like appearance is to be taken up in an orderlymanner. As illustrated, a traverse 30 is used to cause the bundle to bewrapped in a neat package 32 on a bobbin 34. As shown, the package issurface driven by a driven roller 36 in a conventional manner. Othersuitable package building apparatus can be used.

In FIGURE 2 it is seen that the bundle of filaments after thethermochemical treatment is in the form of a thin, flat narrow strip butthat the individual filaments have not lost their identity. The productpossesses substantial longitudinal strength, as well as lateralstrength.

In FIGURE.3 it is seen that the filaments are bonded together to form athin, flat article.

Dihydroxybenzene bond-inducing agents which can be employed includeresorcinol, hydroquinone, and pyrocatechol. The trihydroxybenzenesinclude pyrogallol, for

example. The agents are not limited thereto since derivatives of theforegoing specific compounds also can be used to develop a strongcoherency between the individual nylon filaments. Ordinarily, thedihydroxybenzenes and trihydroxybenzenes are solids at room temperature;and for best results they are rendered fluent before being applied tothe filaments in order that the filaments can be more uniformly coatedtherewith. The benzene compounds can be melted before application.However, the preferred procedure is to dissolve the compounds in asuitable volatile solvent. Dihydroxybenzenes and trihydroxybenzenesgenerally are readily soluble in water, common alcohols (methanol,ethanol, etc.) and ethers (dimethyl ether and the like). The benzenecompounds dissolved in such solvents or other solvents can beconveniently applied to the bundle of filaments in a variety of ways.The compounds can be sprayed, brushed, rolled, padded or applied to thebundle of filaments in other similar ways. The addition of the compoundcan be uniform along the length of the bundle of filaments, or foreconomic reasons can be made only at certain spaced points along thelength of the bundle.

It has been found that preferably a predetermined amount of the benzenecompound is dissolved in methanol. A solution containing about to 80percent dihydroxybenzene or trihydroxybenzene on a weight basis givesexcellent results. The preferred concentration of the benzene compoundin the solution is about 20 to 60 weight percent. The concentration ofthe benzene compound selected, as can be perceived, will depend on manyfactors huch as the methanol of application, the proportion of theliquid picked up by the bundle of filaments, the bundle, etc. Thetemperature of the benzene compound when applied to the bundle offilaments is not too important. It has been found that room temperatureis quite satisfactory as long as the benzene compound is fluent whenapplied, although higher and lower temperatures can be employed.

It is necessary that the bundle of filaments picks up an amount of thebenzene bonding agent sufficient to effect a strong coherency of thebund e of filaments. The amount of multi-hydroxybenzene applied to thebundle of filaments prior to heating can be varied within relativelybroad limits, depending upon the thickness and weight of the structure,the nature and characteristics of the particular nylon filamentsemployed, the individual properties of the bond-inducing agent employed,the physical properties desired in the final straw-like structure, andso forth. Within the broader aspects of the invention from about 5 to 80weight percent multi-hydroxybenzene can be added on a dry basis.

As above indicated, it is necessary to heat the bundle of filamentscarrying the benzene bond-inducing agents in order to effect a strongcohesion of the filaments. Heating of the filaments at an elevatedtemperature is feasible by mean of radiation, convection, or conduction.Preferably, the heat is supplied to the bundle of filaments by contactwith a heated surface supplied by a heated rotating yarn forwarding rollor rolls. In this heating step the temperature of the strands is raisedto about 50 to 250 C., preferably 50150 C., this being below the meltingpoint of the nylon filaments. While heated, the bundle of filaments islaterally pressed in order to effect a better cohesion of the bundle offilaments and to shape the bundle into a straw-like structure. This canbe accomplished by pressing the bundle between two flat or roundedheated surfaces such as provided by nip-forming rolls. However, it isnot essential that the bundle be compressed on both sides. Pressures ofabout 0.5 to 100 pounds per square inch are satisfactory, althoughpressures lesser or greater can be employed. The strength of theresultant structure generally rises up to a point where a higherpressure is used. Generally, excessive, temperatures and pressures oughtto be avoided since they can induce an inferior product to be formed.However, prudent selection of optimum conditions to obtain the desiredproduct is not difficult.

Finally, the resultant straw-like structure is cooled prior to anyfurther operation that undesirably would disturb the individualfilaments of which the structure is composed. The cooling can be quicklyaccomplished by directly applying a coolant thereto. However, merelyallowing the strands to reach equilibrium with room temperature is quitesatisfactory. After cooling, the resulting structure can be used in theconstruction of textile articles nomally made of straw or artificialstraw.

The filamentsare composed of nylon. As is well known, nylon-is along-chain synthetic polymeric amide which has recurring amide groups asan integral part of the main molecular chain, and which is capable ofbeing formed into a filament in which the structural elements areoriented in the direction of the axis. Specific types of nylon fromwhich the filaments can be manufactured include nylon-66(polyhexamethylene adipamide), ny- Ion-6 (polymeric E-aminocaproicacid), nylon-610 (polyhexamethylene sebacamide), nylon-4, nylon-7,nylon-ll, etc., and various fiber-forming copolymers thereof.

The number of nylon filaments which can be bonded together by thepractice of the present invention to obtain the straw-like structure canrange from two to any suitable number of filaments including tow. Thecross section of the filaments may be round, but the cross section canbe multilobal, multifaceted or the like. A bundle of filaments whereinthe filaments have a hexalobal cross section can be shaped into a verydense straw-like structure since the lobes of the filaments will nestinto the concavities of adjacent filaments.

The following examples illustrate specific embodiments of the presentinvention. It is understood that the invention is not limited thereto.All parts and percentages in the examples are by weight unless otherwiseindicated.

Example I A drawn continuous filament nylon-66 yarn composed offilaments and having a total denier of 840 was unwound from a bobbin bymeans of a pair of feed rolls at a rate of feet per minute. The yarn wasmoved across an applicator issuing an aqueous solution containing 33weight percent resorcinol. The yarn then was passed 10 times around aninternally heated feed roll maintained at 180 C., having a peripheralspeed of 180 feet per minute. Between the applicator and the heatedroll, the yarn is passed one time around a conventional draw pin tosuitably flatten the yarn. The yarn leaving the feed roll was wound upon a bobbin in a conventional way. The resultant structure had astraw-like appearance and texture. The longitudinal strength of thestructure was 8 grams per denier. The lateral strength was alsoexcellent.

Example II Instead of employing nylon-66 yarn, nylon-6 yarn was used.The same procedure as set forth in Example I was followed. Similarlyexcellent nylon artificial straw was obtained.

Example III Instead of employing resorcinol, a 35 percent aqueoussolution of pyrocatechol was employed as the bond-inducing agent.Otherwise, the same procedure as in Example I was followed. Similarlyexcellent nylon artificial straw was obtained.

Example IV Example V Instead of employing resorcinol, a 35 percentaqueous solution of pyrogallol was employed as the bond-inducing agent.Otherwise, the same procedure as in Example I was followed. Similarlyexcellent nylon artificial straw was obtained.

In the place of water for rendering the multi-hydroxybenzene fluent,methanol, ethanol and diethyl ether can be used. Moreover, the use of asolvent may be omitted entirely.

There are a number of advantages afforded by the practice of theinvention. A nonwovcn, thin, fiat, narrow band or straw-like structureof nylon is provided. The procedure is simple and inexpensive. Thestraw-like structure can be braided, plaited or woven into articles ofmanufacture such as .bags, hats, etc. Other advantages may be noted.

It is not intended that the invention be limited solely to the detailsof the embodiments set forth above. It will be recognized that numerousmodifications conforming to the spirit of the invention may be made.Therefore, it is intended that the invention be limited only by thescope of the following claims.

What is claimed is:

1. A process for producing a nylon straw-like article comprising:

(a) longitudinally forwarding a bundle of substantially untwisted nyloncontinuous filaments from a source;

(b) applying a 5-80 weight percent solution of a multihydroxybenzenecompound as the sole essential material thereof to the filaments beingforwarded;

(c) flattening the bundle of filaments by pulling same around anonrotatably mounted snubbing surface; (d) wrapping said bundlecontaining said multi-hydroxybenzene compound around a heated yarn for-5 warding means to heat the filaments at a temperature of about 59-250C., said temperature being below the melting point of the filaments, andat a lateral pressure of 0.5 to 100 pounds per square inch; (e) coolingthe filaments; and (f) taking up the resulting article in a uniformmanner. 2. The method of claim 1 wherein the nylon is nylon- 66 ornylon-6.

3. The method of claim 1 wherein the multi-hydroxy- 15 benzene compoundis resorcinol, pyrocatechol, hydroquinone, or pyrogallol.

References Cited UNITED STATES PATENTS 2,031,636 2/1936 Dreyfus 1561802,188,332 1/ 1940 Carothers. 2,349,290 5/1944 Loughborough 117138.82,402,021 6/ 1946 Compton.

25 2,757,111 7/1956 Henderson 15453.6

3,024,589 3/ 1962 Vaughan. 3,042,569 7/1962 Paul 156-180 ALEXANDERWYMAN, Primary Examiner.

30 EARL M. BERGERT, Examiner.

R. J. ROCHE, R. H. CRISS, Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,335,042 August 8 1967 Claude M. Irwin It is hereby certified that errorappears in the above numbered patent requiring correction and that thesaid Letters Patent should read as corrected below Column 3, line 31,for "huch" read such line 31, for "methanol" read method column 6, line6, for

"SQ-250 c." read 50-2s0 c. Signed and sealed this 1st day of October1968c (SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, J r.

Commissioner of Patents Attesting Officer

1. A PROCESS FOR PRODUCING A NYLON STRAW-LIKE ARTICLE COMPRISING: (A)LONGITUDINALLY FORWARDING A BUNDLE OF SUBSTANTIALLY UNTWISTED NYLONCONTINUOUS FILAMENTS FROM A SOURCE; (B) APPLYING A 5-80 WEIGHT PERCENTSOLUTION OF A MULTIHYDROXYBENZENE COMPOUND AS THE SOLE ESSENTIALMATERIAL THEREOF TO THE FILAMENTS BEING FORWARDED; (C) FLATTENING THEBUNDLE OF FILAMENTS BY PULLING SAME AROUND A NONROTATABLY MOUNTEDSNUBBING SURFACE; (D) WRAPPING SAID BUNDLE CONTAINING SAIDMULTI-HYDROXYBENZENE COMPOUND AROUND A HEATER YARN FORWARDING MEANS TOHEAT THE FILAMENTS AT A TEMPERATURE OF ABOUT 59-250*C., SAID TEMPERATUREBEING BELOW THE MELTING POINT OF THE FILAMENTS, AND AT A LATERALPRESSURE OF 0.5 TO 100 POUNDS PER SQUARE INCH; (E) COOLING THEFILAMENTS; AND (F) TAKING UP THE RESULTING ARTICLE IN A UNIFORM MANNER.